"Earlier this year, people in many places wrote about the 40th anniversary of the moment Ken Thompson sat down and started to work on UNIX (which is actually in August). In fact, UNIX celebrates another birthday this year, even though on a slightly smaller scale. In July 1974, exactly 35 years ago, Dennis Ritchie and Ken Thompson published the first version of their seminal paper The UNIX Time-Sharing System in the Communications of the ACM."